Technical University of Berlin

About: Technical University of Berlin is a education organization based out in Berlin, Germany. It is known for research contribution in the topics: Quantum dot & Laser. The organization has 27292 authors who have published 59342 publications receiving 1414623 citations. The organization is also known as: Technische Universität Berlin & TU Berlin.

NiFe‐Based (Oxy)hydroxide Catalysts for Oxygen Evolution Reaction in Non‐Acidic Electrolytes

Abstract: NiFe-based (oxy)hydroxides are highly active catalysts for the oxygen evolution reaction in alkaline electrolyte solutions. These catalysts can be synthesized in different ways leading to nanomaterials and thin films with distinct morphologies, stoichiometries and long-range order. Notably, their structure evolves under oxygen evolution operating conditions with respect to the as-synthesized state. Therefore, many researchers have dedicated their efforts on the identification of the catalytic active sites employing in operando experimental methods and theoretical calculations. These investigations are pivotal to rationally design materials with outstanding performances that will constitute the anodes of practical commercial alkaline electrolyzers. The family of NiFe-based oxyhydroxide catalysts reported in recent years is addressed and the actual state of the research with special focus on the understanding of the oxygen-evolution-reaction active sites and phase is described. Finally, an overview on the proposed oxygen-evolution-reaction mechanisms occurring on NiFe-based oxyhydroxide electrocatalysts is provided.

Functional Materials: From Hard to Soft Porous Frameworks

Abstract: This Review aims to give an overview of recent research in the area of porous, organic-inorganic and purely organic, functional materials. Possibilities for introducing organic groups that exhibit chemical and/or physical functions into porous materials will be described, with a focus on the incorporation of such functional groups as a supporting part of the pore walls. The number of organic groups in the network can be increased such that porous, purely organic materials are obtained.

Event-based Vision: A Survey

Abstract: Event cameras are bio-inspired sensors that differ from conventional frame cameras: Instead of capturing images at a fixed rate, they asynchronously measure per-pixel brightness changes, and output a stream of events that encode the time, location and sign of the brightness changes. Event cameras offer attractive properties compared to traditional cameras: high temporal resolution (in the order of is), very high dynamic range (140dB vs. 60dB), low power consumption, and high pixel bandwidth (on the order of kHz) resulting in reduced motion blur. Hence, event cameras have a large potential for robotics and computer vision in challenging scenarios for traditional cameras, such as low-latency, high speed, and high dynamic range. However, novel methods are required to process the unconventional output of these sensors in order to unlock their potential. This paper provides a comprehensive overview of the emerging field of event-based vision, with a focus on the applications and the algorithms developed to unlock the outstanding properties of event cameras. We present event cameras from their working principle, the actual sensors that are available and the tasks that they have been used for, from low-level vision (feature detection and tracking, optic flow, etc.) to high-level vision (reconstruction, segmentation, recognition). We also discuss the techniques developed to process events, including learning-based techniques, as well as specialized processors for these novel sensors, such as spiking neural networks. Additionally, we highlight the challenges that remain to be tackled and the opportunities that lie ahead in the search for a more efficient, bio-inspired way for machines to perceive and interact with the world.

Large single-mode rib waveguides in GeSi-Si and Si-on-SiO/sub 2/

Abstract: Mode-matching and beam-propagation methods are used to analyze single-mode operation of optical GeSi-Si and Si-SiO/sub 2/ semiconductor rib waveguides. The waveguide dimensions that allow only the fundamental HE/sub 00/ or EH/sub 00/ mode to propagate have been determined. For both material systems, it is found that the rib can be several microns wide and several microns high, thus allowing efficient coupling to single-mode fibers. Numerical examples are given for monomode guiding group-IV materials, but the results apply to III-V rib waveguides. It is shown that single-mode rib guides with large cross sections are feasible as long as the waveguide is at least several millimeters long. >

Wireless Technology in Industrial Networks

Abstract: With the success of wireless technologies in consumer electronics, standard wireless technologies are envisioned for the deployment in industrial environments as well. Industrial applications involving mobile subsystems or just the desire to save cabling make wireless technologies attractive. Nevertheless, these applications often have stringent requirements on reliability and timing. In wired environments, timing and reliability are well catered for by fieldbus systems (which are a mature technology designed to enable communication between digital controllers and the sensors and actuators interfacing to a physical process). When wireless links are included, reliability and timing requirements are significantly more difficult to meet, due to the adverse properties of the radio channels. In this paper, we thus discuss some key issues coming up in wireless fieldbus and wireless industrial communication systems: 1) fundamental problems like achieving timely and reliable transmission despite channel errors; 2) the usage of existing wireless technologies for this specific field of applications; and 3) the creation of hybrid systems in which wireless stations are incorporated into existing wired systems.